The swim beach at the Boulder Reservoir will be closed through Wednesday morning because of elevated levels of bacteria.

The closure was announced by the Boulder Department of Parks and Recreation’s Facebook page Tuesday morning. Officials noted that the unusually high bacteria levels were detected by a standard water sampling test and that fluctuations such as this are common in reservoirs and similar bodies of water.

“The Reservoir is an open, untreated body of water, so elevated levels of bacteria can show up when organic matter flows into the water after rain run off,” the post read.

The beach will remain closed through Wednesday morning at 10 a.m., and may continue to be closed if elevated bacteria levels continue.

Information and updates regarding the closure can be found at twitter.com/BoulderParksRec or by calling 303-441-3461.